HITAḤADUT (Heb. הִתְאַחֲדוּת; full name Mifleget ha-Avodah ha-Ẓiyyonit "Hitaḥadut"), a Socialist-Zionist party formed in 1920 by the union of the Palestine Workers' Party, *Ha-Po'el ha-Ẓa'ir, with a majority of the *Ẓe'irei Zion groups in the Diaspora. Ẓe'irei Zion groups had been formed in Russia at the beginning of the 20th century by young Zionists who espoused the views of Ha-Po'el ha-Ẓa'ir and intended to join that party upon their settlement in Ereẓ Israel. The program of Ẓe'irei Zion, announced at its second congress in Petrograd in 1917, postulated the necessity to establish a Jewish labor commonwealth in the Land of Israel and redirect the Jewish masses in the Diaspora to productive occupations. Ẓe'irei Zion groups were organized in other East European countries, as well as in Germany and Austria (in these last two, under the name Ha-Po'el ha-Ẓa'ir). Later they were also formed in the U.S., Argentina, and South Africa. At the World Conference of Ha-Po'el ha-Ẓa'ir and the Ẓe'irei Zion in Prague (1920), most of the Ẓe'irei Zion groups united with Ha-Po'el ha-Ẓa'ir to form a Zionist party originally called the World Union of the Ha-Po'el ha-Ẓa'ir and Ẓe'irei Zion. At the Third World Conference of the Hitaḥadut in Berlin in 1922, however, its name was changed to Mifleget ha-Avodah ha-Ẓiyyonit "Hitaḥadut" (United Zionist Labor Party, "Hitaḥadut"). A few of the Ẓe'irei Zion groups which espoused a more left-wing, class-oriented ideology formed a separate league, which eventually merged with *Po'alei Zion.
Hitaḥadut, which was represented in the World Zionist Organization and its various bodies, devoted its energies primarily to fostering the *He-Ḥalutz (pioneering) movement in the Diaspora and stimulating immigration to Palestine. It functioned very effectively in both these spheres during the 1920s. It was also able to create an active pioneering movement in Soviet Russia, with a membership of thousands, despite the persecution of Zionism by the Soviet regime. In its Diaspora-oriented activities Hitaḥadut devoted its attention primarily to cultivating economically productive labor. The movement had representatives in the parliaments of several countries (Poland, Lithuania, Latvia, and Romania), in municipal councils, and in the governing bodies of Jewish communities. Unlike other Jewish socialist groups which supported Yiddish, Hitaḥadut championed the revival of Hebrew. It was one of the prime movers of the *Tarbut movement in Eastern Europe, and much of the teaching and administrative personnel of the Hebrew schools came from its ranks. Hitaḥadut also supported the founding of a special pioneering youth movement that crystallized in the late 1920s under the name *Gordonia. Hitaḥadut and Po'alei Zion usually appeared conjointly at Zionist Congresses, and when Ha-Po'el ha-Ẓa'ir and *Aḥdut ha-Avodah in Palestine merged to form the Mifleget Po'alei Ereẓ Yisrael (*Mapai, 1930), the former two groups also amalgamated in 1932 at their world conference in Danzig, and formed the Iḥud Olami.
S. Schiller, Principles of Labor Zionism (1928); A. Tartakower, in: Parteien und Stroemungen im Zionismus in Selbstdarstellungen (1931); idem, in: B. Vlavianos and F. Gross (eds.), Struggle for Tomorrow (1954); A. Levinson, Be-Reshit ha-Tenu'ah (1947); C. Arlosoroff, Der Juedische Volkssozialismus (1919); idem, Das Program der Hitachdut (1923).